Question related to "Do I need to use optical isolators to connect two probe.."

[nzo]

I came across these USB isolators on EBay recently, manufactured by Analog Devices. Here's what they look like and this is the circuit for them. Might such a device help with NeverDie's problem? Haven't tried them myself yet. What do you think?

Thanks all.

[michaeliv]

No this wouldn't help.
USB isolators isolate digital signals with a common ground.
That scenario is about measuring 2 analog signals that do not share a ground - so basically 4 analog signals(or maybe 3) to a common ground and then doing some subtractions on that ... if that makes sense.

But if instead of a digital isolator you would have an analog isolator .. then that would be a differential probe .. and you could use 2 of them to measure that scenario.

[jitter]

I came across these USB isolators on EBay recently, manufactured by Analog Devices. Here's what they look like and this is the circuit for them. Might such a device help with NeverDie's problem? Haven't tried them myself yet. What do you think?

Thanks all.

I have worked with exactly this IC in a USB-interface to create galvanic separation between the device and the PC.
It works OK, but one thing to keep in mind is the limited speed. Even though it's compatible with USB 2.0, max speed is "full" (i.e. 12 Mbps). Here's the datasheet.

No, it won't help with that particular problem. In that thread a single scope is used to simultaneously probe two signals which do not have a common reference. All channels on a scope (except maybe a few handhelds) have all channels connetcted to the same reference, which in turn is connected to safety earth.

The USB isolator only creates a separation between e.g. a USB device and a PC.